Change-speed mechanism.



No. 663,098. Patented Dec. 4, |900.

G. L. MASON L e. E. www-:BELL

CHANGE SPEED MECHANISM.

{Applicaton ld Dec. 22, 1899.)

2 Sheets-Sheet l,

( No Model.)

Inman/ors No. v663,998'.

Patented Dec. ,4, |900. G. L. MASON & G. E. WITHERELL.

CHANGE SPEED MECHANISM.

(Application tiled Dec. 22, 1899.1

2 Sheets-Sheet 2,

(No Model.)

[inve/2mm: y@

Witnesses;

NITE@ bSTATES ATENT Fries.

GEORGE L. MASON, OF 'WAREHOUSE POINT, AND GEORGE E. VVITI-IERELL, OF HARTFORD, CONNECTICUT, ASSIGNORS TO THE HARTFORD MACHINE SCREW COMPANY, OF HARTFORD, CONNECTICUT.

CHANGE-SPEED MECHANISIVI.

SPECIFICATION forming part of Letters Patent No. 663,098, dated December 4, 1900.

4Application filed December 22, 1899. Serial No. 741,272. (No model.)

1o The invention relates to the class of devicesl commonly used on screw-machines to control the rate of speed of the cam-shaft; and the object of the invention is to increase the efliciency of such devices, to obviate the slipping of the belt common to that form in which two pulleys are used as part of the structure, and to provide a device that i's more sensitive to the movement of the controlling parts and which locates the latter in convenient posizo tion for access by the operative.

The invention is shown herein as adapted for use on or as forming part of a screw-machine ofthe common form, although it is not limited to such class of machines alone. Referring to the drawings, Figure lis a top or plan view of the device located on the end of the frame of a screw-machine. Fig. 2 is a viewin horizontal central section on a plane passing through the axis of the worm-shaft, the latter, however, being shown in full lines. Fig. 3 is a View in side elevationof ,the structure. Fig. l is a view in end elevation ofthe same looking from the right as shown in Fig. 3. Fig. 5 is a view in vertical section on a plane denoted by the dotted line at of Fig. 3, showing the ratchet mechanism.

In the accompanying drawings the letter a denotes the frame of the structure, which supports a shaft b in suitable bearings a a2, with a space between the inner ends of the bearing-blocks for the reception of a worm c, 'which is secured to the shaft Z). This frame is secured in any convenient manner to the bed d of the main machine in position to enable the worm c to engage the worm-gear d on the cam-shaft of the screw-machine.

On the shaft b just beyond the bearing a ratchet-wheel e is mounted loosely on the shaft, but secured to a gear-wheel f, also loose on the shaft, except against lateral movement. 5o Beyond and next to the gear-wheel f is another gear-wheel g, which is keyed or otherwise secured to the shaft, so as to turn with it. The pulley 7i is also mounted to turn freely on the shaft, although held against sidewise movement along the shaft, as Vby means of the gear-wheel g on one side and a nut ZL fast to the shaft on the other side. A pinion-shaft 'Z is supported in a socket t in the web of the pulley ZL, and it supports a 6o coupling-pinion Z.: in such manner as to enable ihe pinion to rotate freely on its shaft or to be clamped firmly to the pulley, so as to prevent rotation, although it revolves about the gearsfand g (with which it is in mesh) when the pulley turns. Although this coupling-pinion k, as shown, is of two different diameters, that is not essential, as it is simply one of the several forms in which this part is formed in devices of this class. The 7o only important point is that the pinion turns as one, so that when the part in mesh with the gear-wheel, as g, secured to the shaft, is free to rotate, the other part, which is in mesh with the other gear-wheel f, which is fast to the ratchet, turns with it. The pinion-shaftt' has a limited lengthwise play in its socket in the pulley, so as to operate the I friction-clutch Z to bind the pinion fast to the pulley or permit it to rotate on the pinion- 8o shaft.

The clutch Z comprises a friction member Z', fast to the shaft, and an opposing frictionsurface Z2 on the pinion Zo, and also the friction-disk Z3, fast to the same pinion, and an opposing friction-surface Z4 on the pulley. This subdivision of the clutch is preferred,

owing to the limited space on the side of the pinion and the need of a somewhat extensive contact-surface; but a single clutch-disk may 9o be made to answer the purpose on some sizes of the device.

The hub of the pinion k extends inward along the pinion-shaft until it meets one end of the tubular bushing Zr for the said shaft and which extends' through a socket in the pulley and supports on the other end a cap m, which has a flange resting on the outer end of one of two nuts 'm/ fm2, which are located on a threaded part of the bushing 7c', so as to be accessible for the purpose of adjustment.

On the end of the pinion-shaft a camlever 'n is provided, the forked legs 'n' of the cani straddling the thin part of the end of the shaft and having the cams in contact with the outer face of the cap m. When the driving-pulley is running in a direction to turn the cam-shaft at high speed, the clutch is set to bind the pinion k firmly to the pulley, so that the gear- Wheel g, with which the pinion is in mesh, will be caused to turn with the pulley and drive the shaft. When the cam-lever is moved so as to release the clutch, the pinion lo is left free to turn on its spindle and then, through the medium of the rratchet-wheel e and gear- Wheelsfan d g, drives the shaft at a slow speed in the well-known manner of operation of this class of devices.

The Worin-shaft b is tubular, and through it extends the shipper-rod b', with one end in engagement with the cam-lever n and the other supporting a hand-wheel b2, by means of which the clutch may be operated from the front of the machine. The connection between the shipper-rod and the clutch-lever comprises the common forni of enlarged head o f the shipper-rod, havingaperipheral groove and a collar located in the groove, While the endsy of the yoke on the end of the lever are pivoted to the ring. This permits the pulley and the cam-lever to revolve about the shipperfrod withoutrotating the latter, although leaving it always free to operate the clutch by a sliding movement of the shipper-rod.

`Thisform of coupling is in ordinary use and is thought not to need further description. Near the pawl-shaft into a recess p in the side of the pawl, will bya continuous rotation of the shaft lift the pawl out of the path of movement of the teeth on the ratchet-wheel. There are tWo motions involved in this operationfirst, the Withdrawal of the point of the pawl, and, next, the lifting of the pawl completely out of the way of the teeth. In the operation of the machine the pressure of the ratchet against the end of pawl is at times So great in old forms of the device as to make it extremely diiiicult to lift the pawl out of engagement; but by the means described the pawl is iirst withdrawn, as by the use of the eccentric mount, and then it can be lifted with but slight expenditure of force. in the operation of the device not only in saving of power, but in enabling rapid changes to be made from one rate of speed to the other.

Another feature of improvement resides in the friction-brake s, which controls to a de gree the rotary movement of the Wormshaft. That brake includes a friction-disk s', held in-a socket formed about the shaft, as on the face of one of the bearings, and a disk t,

clamped to the shaft by any con venient means,

is arranged with its face in contact Withthe friction-disk. A slight contact is maintained at all times between the frictionvsurfaces of the brake, so that when a change occurs, as from fast to slow speed, there is no danger of the shaft from its inertia overrunning, so as to cause a tool to continue to operate after the change of speed.

An objection has been found in the use of devices prior to our invention from the fact that the clutches are not instantaneous in action, a certain lost movement occurring between the shaft and pulley before the two are 'in the other.

the other end or the snipper-rod and at the front of the machine there isa like enlargement h3, with a peripheral groove b4, in which airing 1951s located, the trunnions h6 of which arepivoted to the yoke o', formed on one end of the shipper-lever 0, which is pivoted on the bracket a4, projecting from the frame a. The other end of the shipper-lever o bears a pin 02, which projects into the path of movement of a cam on a cam-wheel, which is timed so as to move the shipper-lever at the proper time to automatically move the shipper-rod, so as to clutch or unclutch the pinion 7c on the pulley.

`Another important feature of the invention resides in the device for operating the pawl A bracket a3, projecting from the frame near the ratchet-wheel e, supports a pawl p on anv eccentric fr on the end of the pawlshaft r: The point of the pawl is so located as to engage the teeth on the ratchet-wheel, so as to prevent the rotation of the latter in one direction, but to permit it to freely revolve The pawl is pivoted on the eccentric r, so that the rotation of the pawlshaft will operate first to Withdraw the point of the pawl from the shoulder on the teeth, and then,by means of a pin r2, projecting from clutched together. A further objection re-A sults from the fact of the consequent jar on the machine when the clutch parts comeinto engagement. Devices of the prior art are usually provided with pin-clutches, and it is obvious that with such a clutch the pins are often just past the clutching position. This being the case, when the speed of the parts is changed one member of the clutch is moved rapidly into engagement with the other member, the first member often being in such position that it will have to be rotated at least a half-revolution before the engagement occurs. The sudden impact of the clutch parts is very objectionable and often is of sufficient force to break the clutch-pins. By the use of our improved device these objections are overcome, the action of the clutch connecting the pinion and pulley being instantaneous, and there is no jar when the parts are caused to operate, for as the friction-clutch surfaces come together to clamp the pinion there is just enough slip between the members during the engagement to prevent jar.

What We claim as our invention, and .desire to secure by Letters Patent, is-

l. In achange-speed mechanism, in combination, a shaft, a gear-wheel loosely mounted This aids greatly IOC IIO

on the shaft, means for preventing said gear from rotating, a gear fast to the shaft, a pu 1- ley loose on the shaft, a coupling pinion mounted on said pulley and in mesh with both of said gear-wheels which are dierential, a clutch to clamp the coupling-pinion to the pulley, and means for operating the clutch.

2. In combination in a change-speed mechanism, a shaft, a ratchet-wheel borne on the shaft, a gear-wheel fast to said ratchet-wheel and also borne on the shaft, a gear-wheel fast to the shaft,a pulley loose on the shaft, a coupling-pinion mounted on said pulley and in mesh with both of said gear-wheels which vary in number of teeth, a clutch in operative relation to said coupling-pinion, adapted to secure the pinion to the pulley, and means for operating said clutch.

3. In combination in a change-speed mechanism, a shaft, a pulley loosely mounted on the shaft, intermeshing gears and pinion borne bythe shaft and pulley for varying the speed between said shaft and pulley, means for causing said gear and pinion to operate for the purpose specified, a shifter-rod extending through the shaft, and connections bet-Ween said shifter-rod and pinion, adapted for gripping andreleasing action of the pinion and for clamping the pulley to the shaft.

4. In a change-speed lnechanism, in combination, a shaft, a gear-wheel loosely mounted on the shaft, means for preventing said gear from rotating, a gear fast to the shaft, a pulley loose on the shaft, a coupling pinion mounted on said pulley and in mesh with both of said gear-wheels which Vary in number of teeth, a clutch including a friction-surface located on each side of said couplingpinion, and means for operating the clutch.

5. In combination, a shaft, a pulleyloosely.

mounted on the shaft, a gear secured to the shaft, a pinion mounted on the pulley and in mesh with said gear, a clutch including a friction-surface located on opposite sides of said pinion, and means for operating the clutch.

6. In a speed-changing'mechanism in combination with a shaft and gears and a pulley mounted on said shaft, a pinion-shaft loosely mounted in the pulley, a pinion mounted on the pinion-shaft and in mesh with the gears on the other shaft, and means for causing a movement, lengthwise of the pinion-shaft, between the pulley and said pinion-shaft for clamping the pinion to the pulley.

7. In aspeed-changing mechanism in combination with a shaft and a pulley and gears mounted on the shaft, a pinion-shaft mounted in the pulley and supporting two frictiondisks, a coupling-pinion mounted on the pinion-shaft and located between said frictiondisks, and means for causing a movement, lengthwise of the pinion-shaft, between said shaft and pulley for clamping the pinion to the pulley.

8. In combination in a change-speed mechanism, a shaft, a gear-wheel loosely mounted on the shaft, means for preventing said gearwheel from rotating, a gear fast to the shaft, a pulley loose on the shaft, a pinion-shaft mounted in the pulley, a pinion mounted on the pinion-shaft and in mesh with the gears on the other shaft, and means for causing a movement, lengthwise of the pinion-shaft, between said shaft and pulley to clamp the piniontothe pulley.

9. In combination in a change-speed mechanism, a shaft, a pulley loosely mounted on the shaft, a train of gears connecting the pulley and shaft and including a pinion mounted on a pinion-shaft in the pulley, the pinionshaft, a cam-lever pivoted on the pinion-shaft, and means for operating the cam-lever to clamp the pinion to the pulley.

10. In combination in a change-speed mechanism, a shaft, a pulley loosely mounted on the shaft, a train of gears connecting the pulley and including a pinion on a pinionshaft mounted in the pulley, the pinion-shaft, a cam-lever pivoted to the pinion-shaft and means for operating the cam-lever to cause a movement, lengthwise of the pinion-shaft, between the pulley and shaft whereby the pinion is clamped to the pulley.

1l. In combination in a change-speed mechanism, a shaft, a pulley loosely mounted on the shaft, a train of gears operatively connecting the pulley and shaft and including a pinion on a pinion-shaft mounted in the pulley, a cam-lever mounted on the pinion-shaft, a shipper-rod extending through the main shaft, and operative connections between the shipper-rod and the pinion-shaft, whereby the pinion is clamped to the pulley.

12. In combination in a change-speed mechanism including a shaft, pulley and train of connecting-gears, a ratchet operatively connected with said parts, a pawl lmounted in operative relation to the ratchet, and means arranged for locking the pawl against pressure from the ratchet in returning the pawl to its engaged position, for withdrawing the point of the pawl from the shoulder, and for lifting it from contact with the ratchet.

13. In combination in a change-speed mechanism including a shaft, pulley and train of connecting-gears, a ratchet-wheel operatively connected with said parts, a pawl-shaft, and a pawl eccentrically mounted on said shaft and engaging the ratchet, and means for rotating the paWl-shaft.

14. In combination in a change-speed mechanism including a shaft, pulley and train of connecting-gears, a ratchet-wheel operatively connected with said parts, a paWl-shaft, a pawl having a recess and eccentrically motilited on the shaft and engaging the ratchet, and interengaging parts carried by the pawlshaft, adapted to engage and raise the pawl during the movement of the pawl-shaft.

l5. In a device of the class specified com- ICO IIO

prising a shaft, pulley and train of eonnectits operating means adapted to raise the pawl inggears, and a ratehet- Wheel operatively aftel` it has been disengaged from the ratchet. connected with said parts,a paWl eeeentrioally mounted on a pawl-shaft and adapted to be moved out of engagement with the teeth of the ratchet upon rotation of said shaft, and nterengaging pants between the ratchet and GEORGE L. MASON. GEORGE E. WITHERELL. Witnesses:

ARTHUR B. JENKINS, ERNEST R. SEWARD. 

